1. Field of the Invention
The present invention relates to a single unitary apparatus for reading and/or printing on a recording medium.
2. The Prior Art
In a typical office printer apparatus, the recording medium, normally in the form of paper, is conducted over a drum arranged with a horizontal axis, in front of a print head adapted to move horizontally relative to the drum. Such printer apparatus requires relatively bulky devices for the introduction of the recording medium and its feed, which considerably enlarge the overall structure and bulk of the apparatus. In addition, such apparatus is not suitable for printing stiff and thick recording media, or media which is not able to execute a sharp bend to conform to the surface of the drum.
Copier apparatus has been described which maintains a recording medium in a planar condition, with the printing apparatus suspended above the recording medium. See for example German patent No. OS 3000466. The recording medium is held fast on a planar holding support, and the overall support is moved back and forth in one direction, while the print head simultaneously moves in a direction perpendicular thereto. While this arrangement accommodates thick or stiff recording medium, it presents a number of problems. For example, the recording medium must be held absolutely rigidly on the support for the duration of a printing operation, since even a slight slip in its position leads to recording errors. When a vacuum chamber is provided beneath the holding support, this considerably increases the cost of such apparatus. Also, critical requirements are imposed for the accuracy of the two drives which drive the support and the printing head respectively
It is desirable to provide a combination of an optical read system with a printer, to allow both reading and printing to take place in a single unitary structure. Previous proposals for such a combination such as, for example, European patent No. OS 0025707 lead to a large and bulky structure which is not practical in many office locations. In addition, previous proposals for combinations of these functions involve a great expense in terms of time and complexity for design and production engineering.